I can't post the details yet, but I'm very excited about this current project, which will be unveiled soon. It is a web application written completely in HTML and Javascript that connects to server-side data processing and storage via AJAX using RESTful-style requests. The backend is Drupal, and the frontend is Javascript using ExtJS 2.0 (plus YUI for the History Manager).

The project has been quite a challenge. Traditional web development is much easier, because every page is a complete reload. Adding AJAX functionally makes things slightly more complicated, but going 100% AJAX (to the point where the page never completely reloads) is more difficult than I thought it would be. However, I've developed some pretty solid methods for dealing with page "state", global events, and many other AJAX application challenges. I'm really excited to complete this project and hopefully work on other HTML/JS AJAX applications in the future.